Typewriting-machine



W. A. DOBSON.

TYPEWBlTING MACHINE. APPLICATION FILED JUNE 5, lsfa.

1,335,95 I I Patented A r.6,1920.

a VSHEETSSHEET 1.

Patented Apr. 6, 1920.

3 SHEETS-SHEET 3 nnrr s'rarns PATENT FFICE.

WILLIAM A. DOBSON, OF HARTFORD, CONNECTICUT, ASSIGNOR TO UNDERWOOD TYPE-WRITER COMPANY, OF NEW YORK, N. Y., A CORPORATION OF DELAWARE.

Application filed June 5, 1918.

To all whom it may concern Be it known that 1, WILLIAM A. DonsoN, acitizen of the United States. residing in Hartford, in the county ofHartford and State of Connecticut, have invented certain new and usefulImprovements in Typewriting-Machines, of which the following is aspecification.

My invention relates mainly to the portable class of typewritingmachines, which are small machines with compact parts stamped fromsheet-metal. In such machines, it is extremely desirable that the partsbe not only reliable, but light and cheaply made, and that properadjustments can be readily effected to neutralize any irregularitiesresulting from the bending of metal in the stamping operations, or fromdenting of the parts arising from abuse in the course of long handling.

The present invention centers largely around a platen-shift mechanism ofthe double-shift type; that is to say, a 1nechanism which has both anormal position and two different shifted positions. As hereindisclosed, the case-shift is effected by shifting not only the platenitself, but also the carriage on which the platen is mounted, the railson which the carriage travels, and certain other connected parts. Theplaten it is desirable to shift in the same direction from normal, foreach change of case. It is also desired to provide strong yet easilyadjustable and otherwise manipulatable stops for properly locating thepoint at which the mechanism is arrested when the case is shifted.

I provide a simple locking mechanism for holding the mechanism inwhatever place it is shifted, and this is preferably in the form of anormally-ineffective device which may be set to an ineffective positionwhen a case is shifted, but is automatically released by any subsequentoperation of the case-shift keys.

I make both stops and parts of the locks mainly out of inexpensivestamped parts, and I so shape these parts that the machine is extremelyeasy to assemble.

Other features and advantages will hereinafter appear.

In the accompanying drawings Figure 1 is a side view. largely insection, of a typewriting machine embodying my invention.

Specification of Letters Patent.

TYPEWRITINGr-MACHINE.

Patented Apr. 6, 1920.

Serial No. 238,284.

Fig. 2 is a perspective of the case-shift keys and certain coiiperatingparts.

Fig. 3 is a side view, largely in section, of the parts seen in Fig. 2,with the single shift-key operated. I

Fig. 1 is a view similar to Fig. 3, showing the double shift-keyoperated.

Fig. 5 is a sectional front view of the parts seen in Fig. 2.

Fig. 6 is a skeleton plan View, showing most of the case-shiftmechanism.

The machine herein illustrated is of the front-strike type and comprisescharacter keys 10, which throw type-bars 11 upwardly and rearwardlyagainst the front side of a platen 12, which is journaled in asheetmetal carriage 13. This carriage travels to the left under thecontrol of escapement mechanism (not shown) and is provided withroller-bearings 14- and 15 by which it travels on sheet-metal tracks 16and 17. The tracks 16 and 17 form part of a shift frame which alsoincludes a downwardly-extending member 18 and forwardly-extendingmembers 19, the latter being provided with pivot screws 20 by which theshift frame is pivoted to upper long links 21, said links being in turnpivoted to the main frame 22 by pivots 23 nearly behind butsomewhatbelow the normal position of the pivots 20.

For guiding the shift frame, there is provided a second link or rock-arm24 provided with a stub-shaft 25 on which rests a yoke 26 of the shiftframe, said link 2% being fast at its rear end to atransversely-extending shaft 27, which is encircled by a spring 28. sotensioned as to assist in lifting the shift frame to upper case. Itshould be noted, that as seen in Fig. 6, there is a link 21 and a link24: at each end of the typewriting machine, both links 24 being fast onthe shaft 27, so that the shift frame is raised symmetrically wheneverit is lifted.

For lifting the shift frame there is provided at one side of thekeyboard a capital shift or single shift-key 29 and also a figure shiftor a double shift-key 30, fulcrumed on the opposite ends of a shortshaft 31 which passes through a standard 32 rising from the frame of thetypewriter. The shaft is headed at one end and is held by a screw 32*passing into it, having a head outside the lever of the key 30. Theshift-key-lever 29 is provided with a rearward extension 33 underlyingthe elbowed end 34 of a sheetmetal rock-arm 35 fast on the shaft 27,with the result that when the shift-key 29 is depressed, its rearwardextension 33 lifts the rock-arm 3-5, thereby rocking the. rock-arms 2 fupward, so that the stub-shafts 25 on the latter will lift the shift.The shift-key 29 may be depressed until the shift frame is arrested bythe inwardly-turned heel 36 thereon when said heel strikes a set screw37 on the turned-over end 38 of the arm 39.

,There is aset screw 37 and a heel 36 at each side of the machine,as-shown in Fig. 6, and these set screws are adapted to be independentlyset and then locked by independent lock nuts 4-0, so that the point atwhich the shift frame is arrested on the two sides may be correctlyadjusted identically. Vhen the shift frame is shifted to this p0-sition, the types 4:1 on the type-bar 11 are effective to print instead.of the types 42 which are normally effective to print.

To detain the capital shift-key depressed, a detent cam arm t3n'iay beswung forward (Fig. over a pin if on the sheet-metal lever 45 of theshift-key 29, by pressing rear wardly a finger piece 46 fast to anupwardly-extending arm -1J fast to the cam arm i3 (Figs. 2 and Said armis fast on a short rock shaft 48 ournaled at its ends on short bracketsli) extending inwardly from the frame of the typewriter. This shaft 48forms the connection between the cam arm. and the upwardly-extending arm47, and the finger-piece 46 projects through an opening 50 in-theframework of the typewriter. The lower end of the cam arm' iii is soformed that the lower face 51 thereof has just sufficient slope toenable the pin it to detain the cam arm in position against the tensionof the fiat spring 52, which presses against .a pin on a second cam arm54;, fast to the first cam arnri-Zl, and which nor mally tends to movethe two arms rearwa rdly. The difference in height of the two ends ofthe slope 51 is sosmall that the-cam arn1-431nay bereleased by merelypressing down the shift-key a second time, thereby allowing the springto become effective,- the amount of the second depression being averysmall fraction of an inch, apparently almost entirely absorbed inthe springiness of the key-lever, or other parts, such the rross-bar orgirder 54s" supporting the standard 32,..and not being s1if'fhcinntv tovisibly more theshift frame.

lit-hen it is desired to use the third types on..-the, type-bar 11. thefigure shift-key .30 is depressed, thereby raising the rear end 56 ofits sheet-metal key-lever. sothat said. rear end. .will lift the.turned-over end 3%, raising tie shift frame until it is arrested by setscrews 5Tadjustable in brackets 58. There is oncofthesescrews, at eachmargin of the machine. on .a fiat crossbar 66. i The setscrews .57 maybe. locked-in. place by. means of lock-nuts 6i, and they arrest theshift frame by striking the shelves 71 on the shift frame (describedbelow) In order to permit this greater shifting by the shift-key 30, theset screws 37, which form stops when the shift-key 29 is operated, areautomatically moved to ineffective position. To effect this, the arms39, on which the set screws 37 are mounted, are

formed as the turned-up ends of a bail 62 which is pivoted at 63onscrews Gthreaded in the outer upright sides of the type-writer frame.To this bail is connected a spring 65 which normally swings the ,arms 39so that the set screws??? will be effective to arrest the shift frame.

To effect the automatic swinging of the bail 62, the bail has fastthereto, by means. of a screw 66, an upwardly-turned bracket 67 having arearward extension 68 which overlies a struck-up shelf 69 projecting at.an angle approaching the horizontal from a downward extension of thearm 56, with the result that whenever the shift-key 3O lifts the arm 56,it rocks the bracket 67, thereby rapidly swinging theset screws 37out'ofthe path of the heels 36, to permit the shift frame to rise untilarrested by the set screws 57. The shift frame may be detainedin thisposition by pressing rearwardly the .fingerpieced-6 which will cause thearm 54. teengage a pin 69, (Fig. i) on the lever of the shift-key 30,said pin corresponding to the pin 4 The shift-key 30 may be releasedprecisely as the shift-key 29 is,-by depressing it slightly, thusallowing the spring 52 to swing the arm 5i toineffective position.

The shift frame normally rests on set screws 76,0f which there is one ateach side of the typewriter frame, said set screws being threaded intothe bases of the brackets 58 in such position that the turned-in edges71 of the lower edge of the shift frame normallywrest thereon. Saidscrews 70, like the other set screws. above described, are provided withlock nuts 72 which prevent them from becoming loose.

In. order to hold the shift-key .29 in its normal position, it is drawnupwardly by a spring. 73 anchored in .a post 74 projecting inwardly fromthe front. For preventing the spring from drawing the key 29 too high,the extension of the l y-lever is provided with a downward projection.75 which is adapted to normally rest against the transverse plate orgirder 54 extending transversely of the typewriter frame. The shiftkey30 is providedwith a similar extension 77 also resting against thegirdcrft which prrwents the spring 65 from drawing. it beyond. itsnormal position.

To remove the shift frame from the ma chine. it is. nly 'necessaryitoremove the screws 26: then by lifting therear end of the shift frame itcan be slid out fromunder the screws 57, since the only other supportsof the shift frame are the points where it rests on the stub-shafts 25.

It will be noted that the cam arms 43 and -1 are cut away, as seen at78, above the cams engaged by the pins 44 and 69, to permit thelinger-piece 46 to be operated no matter which of the shift-keys 29 oris de pressed. The surface 78 is formed as a camsnrface with the resultthat when either shift-key is locked down by its cam arm, a

i depression of the other shift-key will cause its pin to be effectiveon the cam-surface 78, with the result that the cam arms a?) and 5stwill be rocked rearwardly, thereby freeing both of the shift-keys.

Variations may be resorted to within the scope of the invention, andportions of the improvements may be used without others.

Having thus described my invention, I claim:

1. In a typewriting machine, the combination with a case-shift mechanismadapted to normally occupy one position, of a key for shifting saidcase-shift mechanism, a lever for said ey, a pin on said lever, an armadapted to be swung over said pin when the lever is depressed, includinga cam surface adapted to cooperate with said pin to hold the armeffective, a spring normally tending to make said arm ineifective, sothat if the key is depressed, when the arm is effective, the spring willmake the arm inef'ective, a second key-lever adapted to differentlyshift said case-shift mechanism, a pin on said second key-lever, arock-she ft to which said arm is fast, and a second arm fast to saidshaft adapted to cooperate with said second pin, to hold secondkey-lever effective and to be released by actuation of the secondkey-lever.

2. In a typewriting machine, the combination with a sheet-metalshift-frame and links on which it is shiftable, of a turnedover ed 'e ofthe sheet-metal, an adjustable stop against which said turned-over edgeis adapted to bear, forming a normal rest for the shift-frame, a secondadjustable stop adapted to limit the throw of said shiftframe byengaging with said turned-over edge, a second turned-over edge, a thirdadjustable stop adapted to arrest said shiftframe by said secondturned-over edge, a spring normally holding said last-named stopeffective a shift-key-lever adapted to shift the shift-frame from thestop against which it normally rests to the last-named stop, and asecond shift-key-lever adapted to shift the shift-frame to thesecond-named stop, said last-named shift-key-lever comprising a memberadapted to swing the third stop to ineffective position when swingingthe shift-frame.

3. In a typewriting machine, the combination with a sheet-metalshift-frame and links on which it is shiftable, of a turnedover edge ofthe sheet-metal, an adjustable stop against which said turned-over edgeis adapted to bear, forming a normal rest for the shift-frame, a secondadjustable stop adapted to limit the throw of said shiftframe byengaging with said turned-over edge, a second turned-over edge, a thirdadjustable stop adapted to arrest said shiftframe by said secondturned-over edge, a pivoted bail on which said third stop is mounted, aspring normally drawing said bail to hold said third stop in effectivepo sition, a shift-key adapted to shift said shiftframe until it strikesagainst said third stop, and a second shift-ley adapted to give afurther shift to said shift-frai'ne and adapted, when shifting theshift-frame, to swing said bail to carry said third stop to ineffectiveposition.

a. In a typewriting machine, the combination with a sheet-metalshift-frame and links on which it is shiftable, of a turned-over edge ofthe sheet1netal, an adjustable stop against which said turned-over edgeis adapted to bear, forming a normal rest for the shift-frame, a secondadjustable stop adapted to limit the throw of said shift frame byengaging with said turned-over edge, a second turned-over edge, a thirdadjustable stop adapted to arrest said shiftframe by said secondturned-over edge, a spring normally holding said last-named stopeffective, a shift-key-lever adapted to shift the shiftframe from thestop against which it normally rests to the last-named stop, a secondshift-key-lever adapted to shift the shift-frame to the second-namedstop. said last-named shift-key-lever comprising a member adapted toswing the third step to ineffective position when swinging theshift-frame, a single bracket on which said first and second stops aremounted, and screws holding said bracket in place, butremovable toenable the shift-frame to be lifted from the machine.

5. In a typewriting machine, the combination with a case-shift mechanismadapted to normally occupy one position, of a pair of keys for shiftingsaid case-shift mechanism to either one of two shifted positions, akey-lever for each key, a pin on each lever, an arm for each. pinadapted to be swung thereover to hold its key down and comprising a camby which the pin prevents the arm from slipping back, a spring normallytending to make said arms ineffective, and a second cam on each armadapted to he struck by the pin if the undepressed key is depressed sothat that key being depressed will cam the arms to ineffective position.

6. In a typewriting machine, the combination with a sheet-metalshift-frame adapted to normally occupy one position, of a key forshifting said sheet-metal shiftframe, a

lever for said key, a pin on said lever, an arm including a cam adaptedto be swung over said pin when the lever is depressed to be held by thepin and hold the lever depressed, a spring normally tending to make saidarm ineffective, a second shift-key comprising a lever to give adifferent shift to said shift-frame, a second pinon said second lever, asecond arm fast to said first arm adapted to be effective on the secondpin to hold the second key eilectivc, a turned-over edge of thesheet-metal, an adjustable stop against which said turned-over edge isadapted to bear forming a normal rest for the shiftframe, a secondadjustable stop adapted to limit the throw of said shift-frame byengaging with the turned-over edge, a second turned over edge, a thirdadjustable stop adapted to arr-est said shift-frame by said secondturned-over edge, a pivoted bail on which said third stop is mounted, aspring normally drawing said bail to hold said third stop in effectiveposition, and a connection whereby one of said shift-keys swings saidbail to make the third stop ineffective.

WlLLIAM A. DOBSON.

Witnesses GEORGE V. CAMPBELL, MORTON S. EAKIN.

